Buried in Joseph White's interesting Wall Street Journal piece about the enormous power of incremental improvements in auto fuel economy (versus so-called moonshots) sits an interesting statistic:

"Mr. Fedewa estimates auto makers can deliver 10% or better fuel efficiency improvement for about $500 a vehicle." (That is Eric Fedewa, described as "a vice president with the automotive consulting firm CSM Worldwide.")

$500 for 10 percent improvement!

What if the government just paid the costs upfront as part of the stimulus package?  Could we invest in fuel economy standards as a sort of time-release piggy bank?